Hydrocarbon conversion process and platinum-germanium catalytic composite for use therein

ABSTRACT

A CATALYTIC COMPOSITE, COMPRISING A COMBINATION OF A PLATINUM GROUP COMPONENT, A GERMANIUM COMPONENT, AND A HALOGEN COMPONENT WITH A POROUS CARRIER MATERIAL IN AMOUNTS SUFFICIENT TO RESULT IN THE COMPOSITE CONTAINING, ON AN ELEMENTAL BASIS, ABOUT 0.01 TO ABOUT 2.0 WT. PERCENT OF THE PLATINUM GROUP METAL, ABOUT 0.01 TO ABOUT 5.0 WT. PERCENT GERMANIUM, AND ABOUT 0.5 TO ABOUT 3.5 WT. PERCENT HALOGEN, IS DISCLOSED. KEY FEATURE OF THE SUBJECT COMPOSITE IS THE USE OF THE GERMANIUM COMPONENT, WHICH IS PREPARED AND MAINTAINED IN AN OXIDATION STATE ABOVE THAT OF THE ELEMENTAL METAL, TO PROMOTE THE PLATINUM GROUP COMPONENT. THE PRINCIPAL UTILITY OF THE SUBJECT COMPOSITE IS IN THE CONVERSION OF HYDROCARBONS, PARTICULARLY IN THE REFORMING OF A GASOLINE FRACTION. A SPECIFIC EXAMPLE OF THE CATALYST DISCLOSED IS A COMBINATION OF PLATINUM, GERMANIUM OXIDE, AND CHLORIDE WITH AN ALUMINA CARRIER MATERIAL IN AMOUNTS SUFFICIENT TO RESULT IN THE COMPOSITE CONTAINING, ON AN ELEMENTAL BASIS, ABOUT 0.05 TO ABOUT 1.0 WT. PERCENT PLATINUM, ABOUT 0.05 TO ABOUT 2.0 WT. PERCENT GERMANIUM, AND ABOUT 0.6 TO ABOUT 1.2 WT. PERCENT CHLORINE.

United States Patent 3,578,584 HYDROCARBON CONVERSION PROCESS ANDPLATINUM-GERMANIUM CATALYTIC COM- POSITE FOR USE THEREIN John C. Hayes,Palatine, Ill., assignor to Universal Oil Products Company, Des Plaines,Ill. No Drawing. Filed May 28, 1969, Ser. No. 828,762 Int. Cl. 80111/08; C10g 35/08 US. Cl. 208-139 20 Claims ABSTRACT OF THE DISCLOSURE Acatalytic composite, comprising a combination of a platinum groupcomponent, a germanium component, and a halogen component with a porouscarrier material in amounts suflicient to result in the compositecontaining, on an elemental basis, about 0.01 to about 2.0 wt. percentof the platinum group metal, about 0.01 to about 5.0 wt. percentgermanium, and about 0.5 to about 3.5 Wt. percent halogen, is disclosed.Key feature of the subject composite is the use of the germaniumcomponent, which is prepared and maintained in an oxidation state abovethat of the elemental metal, to promote the platinum group component.The principal utility of the subject composite is in the conversion ofhydrocarbons, particularly in the reforming of a gasoline fraction. Aspecific example of the catalyst disclosed is a combination of platinum,germanium oxide, and chloride with an alumina carrier material inamounts sulficient to result in the composite containing, on anelemental basis, about 0.05 to about 1.0 wt. percent platinum, about0.05 to about 2.0 wt. percent germanium, and about 0.6 to about 1.2 wt.percent chlorine.

The subject of the present invention is a novel catalyst ic compositewhich has exceptional activity, selectivity, and resistance todeactivation when employed in a hydrocarbon conversion process thatrequires a catalyst having both a hydrogenation-dehydrogenation functionand an acid function. More precisely, the present invention involves anovel dual-function catalytic composite which, quite surprisingly,enables substantial improvements in hydrocarbon conversion processesthat have traditionally utilized a dual-function catalyst to acceleratethe various hydrocarbon conversion reactions associated therewith. Inanother aspect, the invention concerns the improved processes that areproduced by the use of a catalytic composite comprising a combination ofa platinum group component, a germanium oxide component, and a halogencomponent with a porous, high-surface area carrier material;specifically, an improved reforming process which utilizes the subjectcatalyst to markedly improve activity, selectivity, and stabilitycharacteristics associated therewith, to increase yields of C reformateand of hydrogen and to allow operation at high severity conditions notheretofore generally employed in the art of continuous reformingprocesses.

Composites having a hydrogenation-dehydrogenation function and acracking function are widely used today as catalysts in many industries,such as the petroleum and petrochemical industry, to accelerate a widespectrum of hydrocarbon conversion reactions. Generally, the crackingfunction is thought to be associated with an acid-acting material of theporous, adsorptive, refractory oxide type which is typically utilized asthe support or carrier for a heavy metal component such as the metals orcompounds of metals of Group V through V111 of the Periodic TablePatented May ll, 1971 to which are generally attributed thehydrogenation-dehydrogenation function.

These catalytic composites are used to accelerate a wide variety ofhydrocarbon conversion reactions such as hydrocracking, isomerization,dehydrogenation, hydrogenation, desulfurization, cyclization,alkylation, polymerization, cracking hydroisomerization, etc. In manycases, the commercial applications of these catalysts are in processeswhere more than one of these reactions are proceeding simultaneously. Anexample of this type of process is reforming wherein a hydrocarbon feedstream containing paraffins and naphthenes is subjected to conditionswhich promote dehydrogenation of napthenes to aromatics,dehydrocyclization of parafiins to aromatics, isomerization of paraflinsand naphthenes, hydrocracking of naphthenes and parafilns and the likereactions to produce an octane-rich or aromatic-rich product stream.Another example is a hydrocracking process wherein catalysts of thistype are utilized to effect selective hydrogenation and cracking of highmolecular weight unsaturated materials, selective hydrocracking of highmolecular weight materials, and other like reactions, to produce agenerally lower boiling, more valuable output stream. Yet anotherexample is an isomerization process wherein a hydrocarbon fraction whichis relatively rich in straightchain parafiin components is contactedwith a dual-function catalyst to produce an output stream rich inisoparaflin compounds.

Regardless of the reaction involved or the particular process involved,it is of critical importance that the dualfunction catalyst exhibit notonly the capability to initially perform its specified functions, butalso that it has the capability to perform them satisfactorily forprolonged periods of time. The analytical terms used in the art tomeasure how well a particular catalyst performs its intended functionsin a particular hydrocarbon reaction environment are activity,selectivity, and stability. And for purposes of discussion here, theseterms are conveniently defined for a given charge stock as follows: (1)activity is a measure of the catalysts ability to convert hydrocarbonreactants into products at a specified severity level where severitylevel means the conditions usedthat is, the temperature, pressure,contact time, and presence of diluents such as H (2) selectivity refersto the amount of desired product or products obtained relative to theamount of reactants converted; (3) stability refers to the rate ofchange with time of the activity and selectivity parameters-obviouslythe smaller rate implying the more stable catalyst. In a reformingprocess, for example, activity commonly refers to the amount ofconversion that takes place for a given charge stock at a specifiedseverity level and is typically measured by octane number of the Cproduct stream; selectivity usually refers to the relative amount of 0yield that is obtained at the particular severity level; and stabilityis typically equated to the rate of change with time of activity, asmeasured by octane number of C product and of selectivity, as measuredby C yield. Actually, the last statement is not strictly correct becausegenerally a continuous reforming process is run to produce a constantoctane C product with a severity level being continuously adjusted toattain this result; and, furthermore, the severity level is for thisprocess usually varied by adjusting the conversion temperature in thereaction zone so that in point of fact, the rate of change of activityfinds response in the rate of change of conversion temperatures andchanges in this last parameter are customarily taken as indicative ofactivity stability.

As is well known to those skilled in the art, the principal cause ofobserved deactivation or instability of a dual function catalyst when itis used in a hydrocarbon conversion reaction is associated with the factthat coke forms on the surface of the catalyst during the course of thereaction. More specifically, in these hydrocarbon conversion processes,the conditions utilized typically result in the formation of heavy, highmolecular weight, black, solid or semi-solid, carbonaceous materialwhich coats the surface of the catalyst and reduces its activity byshielding its active sites from the reactants. In other words, theperformance of this duabfunction catalyst is sensitive to the presenceof carbonaceous deposits on the surface of the catalyst. Accordingly,the major problem facing workers in this area of the art is thedevelopment of more active and selective catalytic composites that arenot as sensitive to the presence of these carbonaceous materials and/orhave the capability to suppress the rate of the formation of thesecarbonaceous materials on the catalyst. Viewed in terms of performanceparameters, the problem is to develop a dual-function catalyst havingsuperior activity, selectivity, and stability. In particular, for areforming process the problem is typically expressed in terms ofshifting and stabilizing the C;,{ yield-octane relation shipC yieldbeing representative of selectivity, and octane being proportional toactivity.

I have now found a dual-function catalytic composite which possessesimproved activity, selectivity, and stability when it is employed in aprocess for the conversion of hydrocarbons of the type which haveheretofore utilized dual-function catalytic composites such as processesfor isomerization, hydroisomerization, dehydrogenation, desulfurization,denitrogenization, hydrogenation, alkylation, dealkylation,disproportionation, oligomerization, hydrodealkylation, transalkylation,cyclization, dehydrocyclization, cracking, hydrocracking, reforming, andthe like processes. In particular, I have found that a catalyst,comprising a combination of a platinum group component, a germaniumcomponent, and a halogen component with a porous refractory carriermaterial, can enable the performance of a hydrocarbon conversion processutilizing a dual-function catalyst to be substantially improved. Anessential condition associated with the acquisition of this improvedperformance is the oxidation state of the germanium component utilizedin this catalyst. As a result of my investigations, I have determinedthat the germanium component must be utilized in a positive oxidationstate (i.e., either +2 or +4) and that the germanium component must beuniformly distributed throughout the porous carrier material. Inaddition, I have found that in order to achieve the desired oxidationstate and the distribution of the germanium component, the presence of ahalogen component in the composite is essential. Furthermore, thecatalyst must be prepared under carefully controlled conditions as willbe explained hereinafter. In the case of a reforming process, one of theprincipal advantages associated with the use of the novel catalyst ofthe present invention involves the acquisition of the capability tooperate in a stable manner in a high-severity operation; for example, acontinuous reforming process producing a C reformate having an octane ofabout 100 F-l clear and utilizing a relatively low pressure selectedfrom the range of about 50 to about 350 p.s.i.g. In short, the presentinvention essentially involves the finding that the addition of acontrolled amount of an oxidized germanium component to a dual-functionhydrocarbon conversion catalyst containing a platinum group componentand a halogen component enables performance characteristics of thecatalyst to be sharply and materially improved.

It is, accordingly, one object of the present invention to provide ahydrocarbon conversion catalyst having superior performancecharacteristics when utilized in a hydrocarbon conversion process. Asecond object is to provide a catalyst having dual-function hydrocarbonconversion performance characteristics that are relatively insensitiveto the deposition of hydrocarbonaceous material thereon. A third objectis to provide preferred methods of preparation of this catalyticcomposite which insures the achievement and maintenance of itsproperties. Another object is to provide an improved reforming catalysthaving superior activity, selectivity, and stability when employed in alow pressure reforming process. Yet another object is to provide adual-function hydrocarbon conversion catalyst which utilizes arelatively inexpensive component, germanium, to promote a platinum metalcomponent. Still another object is to provide a method of preparation ofa germanium-platinum catalyst which insures the germanium component isin a highly dispersed oxidized state during use in the conversion ofhydrocarbons.

In one embodiment, the present invention is a catalytic compositecomprising a combination of a platinum group component, a germaniumcomponent, and a halogen component with a porous carrier materialwherein the germanium component is present in an oxidation state abovethat of the elemental metaltypically, as germanium oxide. The porouscarrier material is usually a porous, refractory, inorganic oxide, suchas alumina, and the platinum group component and 'germanium componentare usually utilized in relatively small amounts which are effected topromote the desired hydrocarbon conversion reaction.

A second embodiment relates to a catalyst composite comprising acombination of a platinum component, a germanium oxide component, and ahalogen component with an alumina carrier material. These components arepreferably combined in amounts suflicient to result in the finalcomposite containing, on an elemental basis, about 0.01 to about 2.0 wt.percent platinum, about 0.01 to about 5.0 wt. percent germanium andabout 0.5 to about 3.5 wt. percent halogen.

A third embodiment relates to the catalytic composite described in thesecond embodiment wherein the composite, prior to the use thereof in theconversion of hydrocarbons, is reduced with substantially water-freehydrogen under conditions selected to reduce the platinum component butnot the germanium oxide component.

A fourth embodiment relates to a catalytic composite comprising acombination of the pre-reduced catalytic composite of the thirdembodiment with a sulfur component in an amount sufficient toincorporate about 0.05 to about 0.5 Wt. percent sulfur, calculated on anelemental basis.

Another embodiment relates to a process for the conversion of ahydrocarbon comprising contacting the hy drocarbon with the catalyticcomposite of the first embodiment at hydrocarbon conversion conditions.

A preferred embodiment relates to a process for reforming a gasolinefraction which comprises contacting the gasoline fraction and hydrogenwith the catalytic composite described above in the second embodiment atreforming conditions selected to produce a high-octane reformate.

Other objects and embodiments of the present invention relates toadditional details regarding preferred catalytic ingredients,concentration of components in the catalyst composite, suitable methodsof composite preparation, operating conditions for use in thehydrocarbon conversion processes, and the like particulars which arehereinafter given in the following detailed discussion of each of thesefacets of the present invention.

As indicated above, the catalyst of the present invention comprises aporous carrier material or support having combined therewith a platinumgroup component, a germanium component, and a halogen component.Considering first the porous carrier material utilized in the presentinvention, it is preferred that the material be a porous, adsorptive,high-surface area support having a surface area of about 25 to about 500rnF/gm. The porous carrier material should be relatively refractory tothe conditions utilized in the hydrocarbon conversion process, and it isintended to include within the scope of the present invention carriermaterials which have traditionally been utilized in dual-functionhydrocarbon conversion catalysts such as: (l) activated carbon, coke, orcharcoal; (2) silica or silica gel, clays and silicates including thosesynthetically prepared and naturally occurring, which may or may not beacid treated, for example, Attapulgus clay, China clay, diatomaceousearth, fullers earth, kaolin, kieselguhr, pumice, etc.; (3) ceramics,porcelain, crushed firebrick, and bauxite; (4) refractory inorganicoxides such as alumina, titanium dioxide, zirconium dioxide, chromiumoxide, zinc oxide, magnesia, thoria, boria, silica-alumina,silica-magnesia, chromia-alumina, alumina-boria, silica-zirconia, etc.;(5) crystalline aluminosilicates such as naturally occurring orsynthetically prepared mordenite and/or faujasite, either in thehydrogen form or in a form which has been treated with multivalentcations; and, (6) combinations of these groups. The preferred porouscarrier materials for use in the present invention are refractoryinorganic oxides with best results obtained with an alumina carriermaterial. Suitable alumina materials are the crystalline aluminas knownas the gamma-, eta-, and theta-alumina with gammaor eta-alumina givingbest results. In addition, in some embodiments the alumina carriermaterial may contain minor proportions of other well known refractoryinorganic oxides such as silica, zirconia, magnesia, etc.; however, thepreferred carrier material is substantially pure gammaor eta-alumina.Preferred carrier materials have an apparent bulk density of about 0.30to about 0.70 gm./ cc. and surface area characteristics such that theaverage pore diameter is about 20 to 300 angstroms, the pore volume isabout 0.10 to about 1.0 ml./gm. and the surface area is about 100 toabout 500 m. gm. In general, best results are typically obtained with agammaalumina carrier material which is used in the form of sphericalparticles having: a relatively small diameter (i.e., typically about Ainch), an apparent bulk density of about 0.5 gm./cc., a pore volume ofabout 0.4 ml./gm., and a surface area of about 175 m. /gm.

The preferred alumina carrier material may be prepared in any suitablemanner and may be synthetically prepared or natural occurring. Whatevertype of alumina is employed it may be activated prior to use by one ormore treatments including drying, calcination, steaming, etc., and itmay be in a form known as activated alumina, activated alumina ofcommerce, porous alumina, alumina gel, etc. For example, the aluminacarrier may be prepared by adding a suitable alkaline reagent, such asammonium hydroxide, to a salt of aluminum such as aluminum chloride,aluminum nitrate, etc., in an amount to form an aluminum hydroxide gelwhich upon drying and calcining is converted to alumina. The alumina maybe formed in any desired shape such as spheres, pills, cakes,extrudates, powders, granules, etc. and utilized in any desired size.For the purpose of the present invention, a particularly preferred formof alumina is the sphere; and alumina spheres may be continuouslymanufactured by the well known oil drop method which comprises: formingan alumina hydrosol by any of the techniques taught in the art andpreferably by reacting aluminum metal with hydrochloric acid, combiningthe hydrosol with a suitable gelling agent and dropping the resultantmixture into an oil bath maintained at elevated temperatures. Thedroplets of the mixture remain in the oil bath until they set and formhydrogel spheres. The spheres are then continuously withdrawn from theoil bath and typically subjected to specific aging treatments in oil andan ammoniacal solution to further improve their physicalcharacteristics. The resulting aged and gelled particles are then washedand dried at a relatively low temperature of about 300 F. to about 400F. and subjected to a calcination procedure at a temperature of about850 F. to about 1300 F. for a period of about 1 to about 20 hours. Thistreatment effects conversion of the alumina hydrogel to thecorresponding crystalline 6 gamma-alumina. See the teachings of U.S.Pat. No. 2,620,314 for additional details.

One essential constituent of the composite of the present invention is agermanium component, and it is an essential feature of the presentinvention that the germanium component is present in the composite in anoxidation state above that of the elemental metal. That is to say, thegermanium component will exist in the catalytic composite in either the+2 or +4 oxidation state with the latter being the most likely state.Accordingly, the germanium component will be present in the composite asa chemical compound, such as the oxide, sulfide, halide, etc., whereinthe germanium is in the required oxidation state, or as a chemicalcombination with the carrier material in which combination the germaniumexists in this higher oxidation state. On the basis of the evidencecurrently available, it is believed that germaniurn component in thesubject composite exists as germanous or germanic oxide. It is importantto note that this limitation on the state of the germanium componentrequires extreme care in the preparation and use of the subjectcomposite in order to insure that it is not subjected to hightemperature reduction conditions effective to produce the germaniummetal. This germanium component may be incorporated in the catalyticcomposite in any suitable manner known to the art such as bycoprecipitation or cogellation with the porous carrier. material, ionexchange with the gelled carrier material or impregnation with thecarrier material either after or before it is dried and calcined. It isto be noted that it is intended to include within the scope of thepresent invention all conventional methods for incorporating a me talliccomposite in a catalytic composite and the particular method ofincorporation used is not deemed to be an essential feature of thepresent invention. One method of incorporating the germanium componentinto the catalytic composite involves coprecipitatiug the germaniumcomponent during the preparation of the preferred carrier material,alumina. This method typically involves the addition of a suitablesoluble germanium compound such as germanium tetrachloride to thealumina hydrosol and then combining the hydrosol with a suitable gellingagent and dropping the resulting mixture into an oil bath, etc., asexplained in detail hereinbefore. After drying and calcining theresulting gelled carrier material there is obtained an intimatecombination of alumina and germanium oxide. A preferred method ofincorporating the germanium component into the catalytic compositeinvolves utilization of a soluble, decomposable compound of germanium toimpregnate the porous carrier material. In general, the solvent used inthis impregnation step is selected on the basis of the capability todissolve the desired germanium compound and is preferably an aqueous,acidic solution. Thus, the germanium component may be added to thecarrier material by commingling the latter with an aqueous, acidicsolution of suitable germanium salt or suitable compound or germaniumsuch as germanium tetrachloride, germanium difluoride, germaniumtetrafluoride, germanium di-iodide, germanium monosultide, and the likecompounds. A particularly preferred impregnation solution comprisesgermanium mono-oxide dissolved in chlorine Water. In general, thegermanium component can be impregnated either prior to, simultaneouslywith, or after the platinum group component is added to the carriermaterial. However, I have found that excellent results are obtained whenthe germanium component is impregnated simultaneously with the platinumgroup component. In fact, I have determined that a preferredimpregnation solution contains chloroplatinic acid, hydrogen chloride,and germanous oxide dissolved in chlorine Water. Following theimpregnation step, the resulting composite is dried and calcined asexplained hereinafter.

Regardless of which germanium compound is used in the preferredimpregnation step, it is important that the germanium component beuniformly distributed throughout the carrier material. In order toachieve this objective it is necessary to maintain the pH of theimpregnation solution in a range of about 1 to about 7 and to dilute theimpregnation solution to a volume which is substantially in excess ofthe volume of the carrier material which is impregnated. It is preferredto use a volume ratio of impregnation solution to carrier material of atleast 15:1 and preferably about 2:1 to about 10:1 or more. Similarly, itis preferred to use a relatively long contact time during theimpregnation step ranging from about A hour up to about /2 hour or morebefore drying to remove excess solvent in order to insure a highdispersion of the germanium component on the carrier material. Thecarrier material is, likewise, preferably constantly agitated duringthis preferred impregnation step.

As indicated above, the catalyst of the present invention also containsa platinum group component. Although the process of the presentinvention is specifically directed to the use of a catalytic compositecontaining platinum, it is intended to include other platinum groupmetals such as palladium, rhodium, ruthenium, osmium, and iridium. Theplatinum group component, such as platinum, may exist within the finalcatalytic composite as a compound such as an oxide, sulfide, halide,etc., or as an elemental metal. Generally, the amount of the platinumgroup component present in the final catalyst composite is smallcompared to the quantities of the other components combined therewith.In fact, the platinum group component generally comprises about :01 toabout 2.0 wt. percent of the final catalytic composite, calculated on anelemental basis. Excellent results are obtained when the catalystcontains about 0.05 to about 1.0 wt. percent of the platinum groupmetal. The preferred platinum group component is platinum or a compoundof platinum.

The platinum group component may be incorporated in the catalyticcomposite in any suitable manner such as coprecipitation or cogellationwith the preferred carrier material, or ion exchange or impregnationthereof. The preferred method of preparing the catalyst involves theutilization of a water-soluble, decomposable compound of a platinumgroup metal to impregnate the carrier material. Thus, the platinum groupcomponent may be added to the support by commingling the latter with anaqueous solution of chloroplatinic acid. Other watersoluble compounds ofplatinum may be employed in impregnation solutions and include ammoniumchloroplatinate, bromoplatinic acid, platinum dichloride, platinumtetrachlorde hydrate, platinum dichlorocarbonylclichloride, dinitrodiaminoplatinum, etc. The utilization of a platinum chloride compoundsuch as chloroplatinic acid is preferred since it facilitates theincorporation of both the platinum component and at least a minorquantity of the halogen component in a single step. Hydrogen chloride isalso generally added to the impregnation solution in order to furtherfacilitate the incorporation of the halogen component and to aid in thedistribution of the metallic component throughout the carrier material.In addition, it is generally preferred to impregnate the carriermaterial after it has been calcined in order to minimize the risk ofwashing away the valuable platinum metal compounds; however, in somecases it may be advantageous to impregnate the carrier material when itis in a gelled state. Following the impregnation, the resultingimpregnated support is dried and subjected to a high temperaturecalcination or oxidation technique which is explained hereinafter.

Another essential constituent of the subject composite is the halogencomponent. Although the precise form of the chemistry of the associationof the halogen component with the carrier material is not entirelyknown, it is customary in the art to refer to the halogen component asbeing combined with the carrier material or with the other ingredientsof the catalyst. This combined halogen may be either fluorine, chlorine,iodine, bromine, or mixtures thereof. Of these, fluorine andparticularly chlorine are preferred. The halogen may be added to thecarrier material inany suitable manner either during preparation of thecarrier material or before or after the addition of the othercomponents. For example, the halogen may be added at any stage of thepreparation of the carrier material or to the calcined carrier materialas an aqueous solution of an acid such as hydrogen fluoride, hydrogenchloride, hydrogen bromide, etc. The halogen component or a portionthereof may be composited with the carrier material during theimpregnation of the latter with the platinum group component; forexample, through the utilization of a mixture of chloroplatinic acid andhydrogen chloride. In another situation, the alumina hydrosol which istypically utilized to form the preferred alumina carrier material maycontain halogen and thus contribute at least a' portion of the halogencomponent to the final composite. For reforming, the halogen is combinedwith the carrier material in an amount sufiicient to result in a finalcomposite that contains about 0.5 to about 3.5 wt. percent andpreferably about 0.6 to about 1.2 by weight of the halogen calculated onan elemental basis. In isomerization or hydrocracking embodiments, it isgenerally preferred to utilize relatively larger amounts of halogen inthe catalysttypically ranging up to about 10 wt. percent halogencalculated on an elemental basis, and, more preferably, about 1.0 toabout 5.0 wt. percent. Ina reforming embodiment, the preferred halogencomponent is chlorine or a compound thereof.

The halogen component is utilized in the subject composite for twopurposes: one involves the traditional enhancement of the acidicfunction of the resulting composite, the other involves the achievementand maintenance of a uniform distribution of the oxidized germaniumcomponent in the carirer material. I have observed that a highdispersion of small crystallites of the germanium component in thecarrier material is essential for the maintenance of the germaniumcomponent in an oxidized state under the reduction conditions used inthe hereinafter described reduction step as well as the reductionconditions encountered in the use of the composite in, for example, areforming process. One of the principal effects of incorporating thehalogen component in the composite is that it acts to hold or fix thegermanium component in a highly dispersed state Where it highlyresistant to the subsequent reduction conditions. Despite thisresistance, it is still necessary to carefully control the conditions towhich the composite is subjected in order to insure that the germaniumis maintained in an oxidized state; that is to say, prolonged exposureof the composite to hydrogen at temperatures substantially above about1000 F. are to be avoided.

Relative to the amount of the germanium component contained in thecomposite, it is preferably sufiicient to constitute about 0.01 to about5.0 wt. percent of the final composite, calculated on an elementalbasis, although substantially higher amounts of germanium may beutilized in some cases. In a reforming embodiment best results aretypically obtained with about 0.05 to about 2.0 wt. percent germanium.In the case where the germanium component is incorporated in thecatalyst by coprecipitating it with the preferred alumina carriermaterial, it is within the scope of the present invention to preparecomposites containing up to 30 wt. percent germanium, calculated on anelemental baiss. Regardless of the absolute amounts of the germaniumcomponent and the platinum group component utilized, the atomic ratio ofgermanium to the platinum group metal contained in the catalyst ispreferably selected from the range of about 0.1: l to about 5:1 withbest results achieved at an atomic ratio of about 0.2:1 to 3.5 :1. Thisis particularly true when the total content of the germanium componentplus the platinum group component in the catalytic composite is fixed inthe range of about 0.1 to about 3.0 wt. percent thereof, calculated onan elemental germanium and platinum group metal basis. Accordingly,examples of especially preferred catalytic composites are as follows:(1) a catalytic composite comprising 0.5 wt. percent germanium, 0.75 wt.percent platinum, and 0.6 to 1.2 wt. percent halogen combined 'with analumina carrier material, (2) a catalytic composite comprising 0.1 Wt.percent germanium, 0.65 'wt. percent platinum, and 0.6 to 1.2 wt.percent halogen combined with an alumina carrier material, (3) acatalytic composite comprising 0.375 wt. percent germanium, 0.375 wt.percent platinum, and 0.6 to 1.2 wt. percent halogen combined with analumina carrier material, (4) a catalytic composite comprising 1.0 wt.percent germanium, 0.5 Wt. percent platinum, and 0.6 to 1.2 Wt. percenthalogen combined with an alumina carrier material, (5) a catalyticcomposite comprising 0.25 wt. percent germanium, 0.375 wt. percentplatinum, and 0.6 to 1.2 -wt. percent halogen combined with an aluminacarrier material, (6) a catalytic composite comprising 0.8 vvt. percentgermanium, 0.375 wt. percent platinum, and 0.6 to 1.2 wt. percenthalogen combined with an alumina carrier material, and, (7) a. catalyticcomposite comprising 0.5 Wt. percent germanium, 0.375 wt. percentplatinum, and 0.6 to 1.2 wt. percent halogen combined with an aluminacarrier material.

Regardless of the details of how the components of the catalyst arecombined with the porous carrier material, the final catalyst generallywill be dried at a temperature of about 200 to about 600 F. for a periodof from about 2 to about 24 hours or more, and finally calcined at atemperature of about 700 F. to about 1100" F. in an air atmosphere for aperiod of about 0.5 to about 10 hours in order to convert the metalliccomponents substantially to the oxide form. Best results are generallyobtained when the halogen content of the catalyst is adjusted during thecalcination step by including a halogen or a halogencontaining compoundin the air atmosphere utilized. In particular, when the halogencomponent of the catalyst is chlorine, it is preferred to use a moleratio of H 0 to HCl of about 20:1 to about 100:1 during at least aportion of the calcination step in order to adjust the final chlorinecontent of the catalyst to a range of about 0.6 to about 1.2 wt.percent.

It is preferred that the resultant calcined catalytic composite besubjected to a substantially water-free reduction step prior to its usein the conversion of hydrocarbons. This step is desired to insure auniform and finely di-vided dispersion of the metallic componentthroughout the carrier material. Preferably, substantially pure and dryhydrogen (i.e., less than 20 vol. ppm. H O) is used as the reducingagent in this step. The reducing agent is contacted with the calcinedcatalyst at conditions including a temperature of about 800 F. to about1000 F. selected to reduce the platinum group component to the metallicstate while maintaining the germanium component in an oxidized state.This reduction step may be performed in situ as part of a start-upsequence if precautions are taken to predry the plant to a substantiallywater-free state and if substantially Water-free hydrogen is used. Inorder to minimize the danger of reducing the germanium component duringthis step, the duration of this step is preferably less than two hours,and, more typically, about one hour.

The resulting reduced catalytic composite may, in some cases, bebeneficially subjected to a presulfiding step designed to incorporate inthe catalytic composite from about 0.05 to about 0.50 wt. percent sulfurcalculated on an elemental basis. Preferably, this presulfidingtreatment takes place in the presence of hydrogen and a suitablesulfur-containing compound such as hydrogen sulfide, lower molecularweight mercaptans, organic sulfides, etc. Typically, this procedurecomprises treating the reduced catalyst with a sulfiding gas such as amixture of hydrogen and hydrogen sulfide having about 10 moles 10 ofhydrogen. per mole of hydrogen sulfide at conditions sufiicient toeffect the desired incorporation of sulfur, generally including atemperature ranging from about 50 F. up to about 1000 F. It is generallya good practice to perform this presulfiding step under substantiallywaterfree conditions.

According to the present invention, a hydrocarbon charge stock andhydrogen are contacted with a catalyst of the type described above in ahydrocarbon conversion zone. This contacting may be accomplished byusing the catalyst in a fixed bed system, a moving bed system, afluidized bed system, or in a batch type operation; however, in view ofthe danger of attrition losses of the valuable catalyst and of wellknown operational advantages, it is preferred to use a fixed bed system.In this system, a hydrogen-rich gas and the charge stock are preheatedby any suitable heating means to the desired reaction temperature andthen are passed into a conversion zone containing a fixed bed of thecatalyst type previously characterized. It is, of course, understoodthat the conversion zone may be one or more separate reactors withsuitable means therebetween to insure that the desired conversiontemperature is maintained at the entrance to each reactor. It is also tobe noted that the reactants may be contacted With the catalyst bed ineither upward, downward, or radial flow fashion with the latter beingpreferred, In addition, it is to be noted that the reactants may be in aliquid phase, a mixed liquid-vapor phase, or a vapor phase when theycontact the catalyst, With best results obtained in the vapor phase.

In the case where the catalyst of the present invention is used in areforming operation, the reforming system will comprise a reforming zonecontaining a fixed bed of the catalyst type previously characterized.This reforming zone may be one or more separate reactors with suitableheating means therebetween to compensate for the endothermic nature ofthe reactions that take place in each catalyst bed. The hydrocarbon feedstream that is charged to this reforming system will comprisehydrocarbon fractions containing naphthenes and parafiins that boilwithin the gasoline range. The preferred charge stocks are thoseconsisting essentially of naphthenes and paraflins, although in manycases aromatics are also present. This preferred class includes straightrun gasolines, natural gasolines, synthetic gasolines, and the like. Onthe other hand, it is frequently advantageous to charge thermally orcatalytically cracked gasolines or higher boiling fractions thereof.Mixtures of straight run and cracked gasolines can also be used toadvantage. The gasoline charge stock may be a full boiling gasolinehaving an initial boiling point of from about 50 F. to about F. and anend boiling point within the range of from about 325 F. to about 425 F.,or may be a selected fraction thereof which generally will be a higherboiling fraction commonly referred to as a heavy naphthafor example, anaphtha boiling in the range of C7 to 400 F. In some cases, it is alsoadvantageous to charge pure hydrocarbons or mixture of hydrocarbons thathave been extracted from hydrocarbon distillates-for example, straightchain paraflins which are to be converted to aromatics. It is preferredthat these charge stocks be treated by conventional catalyticpretreatment methods such as hydrorefining, hydrotreating,hydrodesulfurization, etc., to remove substantially all sulfurous,nitrogenous, and Water-yielding contaminants therefrom, and to saturateany olefins that may be contained therein.

In other hydrocarbon conversion embodiments, the charge stock will be ofthe conventional type customarily used for the particular kind ofhydrocarbon conversion being effected. For example, in typicalisomerization embodiments the charge stock can be a paratfinic stockrich in C to C normal paraffins, or a normal butane-rich stock, or ann-hexane-rich stock, or a mixture of alkylaromatics such as a mixture ofxylenes, etc. In hydrocracking embodiments the charge stock will betypically a gas oil, heavy cracked cycle oil, etc. Likewise, purehydrocarbons or substantially pure hydrocarbons can be converted to morevaluable products by using the catalyst of the present invention in anyof the hydrocarbon conversion processes known to the art that use adual-function catalyst.

In a reforming embodiment, it is generally preferred that the novelcatalytic composite is utilized in a substantially water-freeenvironment. Essential to the achievement of this condition in thereforming zone is the control of the water level present in the chargestock and the hydrogen stream which is being charged to the zone. Bestresults are ordinarily obtained when the total amount of water enteringthe conversion zone from any source is held to a level less than 50p.p.m. and preferably less than 20 p.p.m., expressed as weight ofequivalent water in the charge stock. In general, this can beaccomplished by careful control of the water present in the charge stockand in the hydrogen stream; the charge stock can be dried by using anysuitable drying means known to the art such as a conventional solidadsorbent having a high selectivity for water; for instance, sodium orcalcium crystalline aluminosilicates, silica gel, activated alumina,molecular sieves, anhydrous calcium sulfate, high surface area sodium,and the like adsorbents. Similarly, the water content of the chargestock may be adjusted by suitable stripping operations in afractionation column or like device. And in some cases, a combination ofadsorbent drying and distillation drying may be used advantageously toeffect almost complete removal of Water from the charge stock.Preferably, the charge stock is dried to a level corresponding to lessthan 20 p.p.m. of H equivalent. In general, it is preferred to dry thehydrogen stream entering the hydrocarbon conversion zone down to a levelof about volume p.p.m. of water or less. This can be convenientlyaccomplished by contacting the hydrogen stream with a suitable desiccantsuch as those mentioned above.

In the reforming embodiment, an effluent stream is withdrawn from thereforming zone and passed through a cooling means to a separation zone,typically maintained at about 25 to 100 F. wherein a hydrogen-rich gasis separated from a high octane liquid product, commonly designated as areformate. Preferably, at least a portion of this hydrogen-rich gas iswithdrawn from the separating zone and passed through an adsorption zonecontaining an adsorbent selective for water. The resultant substantiallywater-free hydrogen stream is then recycled through suitable compressingmeans back to the reforming zone. The liquid phase from the separatingzone is then typically withdrawn and commonly treated in a fractionatingsystem in order to adjust its butane concentration in order to controlfront-end volatility of the resulting reformate.

The conditions utilized in the numerous hydrocarbon conversionembodiments of the present invention are those customarily used in theart for the particular reaction or combination of reactions that is tobe effected. For instance, alkylaromatic and parafin isomerizationconditions include: a temperature of about 32 F. to about 100 F. andpreferably about 75 to about 600 F.; a pressure of atmospheric to about100 atmospheres; hydrogen to hydrocarbon mole ratio of about 0.5 toabout 2.0: 1, and an LHSV (calculated on the basis of equivalent liquidvolume of the charge stock contacted with the catalyst per hour dividedby the volume of conversion zone containing catalyst) of about 0.2 hIZto 10 hr? Dehydrogenation conditions include: a temperature of about 700to about 1250 F., a pressure of about 0.1 to about 10 atmospheres, aliquid hourly space velocity of about 1 to 40 hr. and a hydrogen tohydrocarbon mole ratio of about 1:1 to :1. Likewise, typicallyhydrocracking conditions include: a pressure of about 500 p.s.i.g. toabout 3000 p.s.i.g.; a temperature of about 400 F. to about 900 R; anLHSV of about 0.1 hr.* to about 10 lll." and hydrogen circulation ratesof about 1000 to 10,000 s.c.f. per barrel of charge.

In the reforming embodiment of the present invention,

the pressure utilized is preferably selected in the range of about 50p.s.i.g. to about 350 p.s.i.g. In fact, it is a singular advantage ofthe present invention that it allows stable operation at lower pressurethan have heretofore been successfully utilized in so-called continuousreforming systems (i.e., reforming for periods of about 15 to about 200or more barrels of charge per pound of catalyst without regeneration).In other words, the catalyst of the present invention allows theoperation of a continuous reforming system to be conducted at lowerpressure (i.e., 50 to 350 p.s.i.g.) for about the same or bettercatalyst life before regeneration as has been heretofore realized withconventional catalysts at higher pressures (i.e., 400 to 600 p.s.i.g.).

Similarly, the temperature required for reforming is generally lowerthan that required for a similar reforming operation using a highquality catalyst of the prior art. This significant and desirablefeature of the present invention is a consequence of the selectivity ofthe catalyst of the present invention for the octane-upgrading reactionsthat are preferably induced in a typical reforming operation. Hence, thepresent invention requires a temperature in the range of from about 800F. to about 1100 F. and preferably about 900 F. to about 1050 F. As iswell known to those skilled in the continuous reforming art, the initialselection of the temperature within this broad range is made primarilyas a function of the desired octane of the product reformate consideringthe characteristics of the charge stock and of the catalyst. Ordinarily,the temperature then is thereafter slowly increased during the run tocompensate for the inevitable deactivation that occurs to provide aconstant octane product. Therefore, it is a feature of the presentinvention that the rate at which the temperature is increased in orderto maintain a constant octane product, is substantially lower for thecatalyst of the present invention than for a high quality reformingcatalyst which is manufactured in exactly the same manner as thecatalyst of the present invention except for the inclusion of thegermanium component. Moreover, for the catalyst of the presentinvention, the C yield loss for a given temperature increase issubstantially lower than for a high quality reforming catalyst of theprior art. In addition, hydrogen production is substantially higher.

The reforming embodiment of the present invention also typicallyutilizes sufficient hydrogen to provide an amount of about 2.0 to about20 moles of hydrogen per mole of hydrocarbon entering the reformingzone, with excellent results being obtained when about 5 to about 10moles of hydrogen are used per mole of hydrocarbon. Likewise, the liquidhourly space velocity (LHSV) used in reforming is selected from therange of about 0.1 to about 10.0 hr. with a value in the range of about1.0 to about 5.0 hr. being preferred. In fact, it is a feature of thepresent invention that, for the same severity level, it allowsoperations to be conducted at higher LHSV than normally can be stablyachieved in a continuous reforming process with a high quality reformingcatalyst of the prior art. This last feature is of immense economicsignificance because it allows a continuous reforming process to operateat the same throughput level with less catalyst inventory than thatheretofore used with conventional reforming catalysts at no sacrifice incatalyst life before regeneration.

The following examples are given to illustrate further the preparationof the catalytic composite of the present invention and the use thereofin the conversion of hydrocarbons. It is understood that the examplesare given for the sole purpose of illustration and are not to beconsidered to limit unduly the generally broad scope and spirit of theappended claims.

EXAMPLE I This example demonstrates a preferred method of preparing thepreferred catalytic composite of the present invention.

13 An alumina carrier material comprising A inch spheres was preparedby: forming an aluminum hydroxyl chloride sol by dissolvingsubstantially pure aluminum pellets in a hydrochloric acid solution,adding hexamethylenetetramine to the resulting sol, getting theresulting solution by dropping it into an oil bath to form sphericalparticles of alumina hydrogel. The resulting hydrogel particles werethen aged and washed with an ammoniacal solution and finally dried andcalcined at an elevated temperature to form spherical particles ofgamma-alumina containing about 0.3 wt. percent combined chloride.Additional details as to this method of preparing the preferred carriermaterial are given in the teachings of U8. Pat. No. 2,620,314.

A measured amount of germanium dioxide crystals was placed in aporcelain boat and subjected to a reduction treatment with substantiallypure hydrogen at a temperature of about 650 C. for about 2 hours. Theresulting grayish-black solid material was dissolved in chlorine waterto form an aqueous solution of germanium monooxide. An aqueous solutioncontaining chloroplatinic acid and hydrogen chloride was then prepared.The two solutions were then intimately admixed and used to impregnatethe gamma-alumina particles in amounts, respectively, calculated toresult in a final composite containing 0.25 wt. percent Ge and 0.375 wt.percent Pt. In order to insure uniform distribution of both metal liccomponents throughout the carrier material, this impregnation step wasperformed by adding the carrier material particles to the impregnationmixture with con stant agitation. In addition, the volume of thesolution was two times the volume of the carrier material particles. Theimpregnation mixture was maintained in contact with the carrier materialparticles for a period of about A2 hour at a temperature of about 70 F.Thereafter, the temperature of the impregnation mixture was raised toabout 225 F. and the excess solution was evaporated in a period of about1 hour. The resulting dried particles were then subjected to acalcination treatment in an air atmosphere at a temperature of about 925F. for about 1 hour. The calcined spheres were then contacted with anair stream containing H and HCl in a mole ratio of about 40:1 for about4 hours at 975 F. in order to adjust the halogen content of the catalystparticles to a value of about 0.90.

The resulting catalyst particles were analyzed and found to contain, onan elemental basis, about 0.375 wt. percent platinum, about 0.25 wt.percent germanium, and about 0.35 wt. percent chloride.

Thereafter, the catalyst particles were subjected to a dry pre-reductiontreatment by contacting them with a substantially pure hydrogen streamcontaining less than 20 vol. p.p.m. H O at a temperature of about l000F., a pressure slightly above atmospheric and a flow rate of thehydrogen stream through the catalyst particles corresponding to a gashourly space velocity of about 720 hrr This pre-reduction step was for aduration of about 1 hour.

EXAMPLE II In order to compare the novel catalytic composite of thepresent invention with those of the prior art in a manner calculated tobring out the interaction between the germanium component and theplatinum component, a comparison test was made between the catalyst ofthe present invention which was prepared according to the method givenin Example I and a reforming catalyst of the prior art which containedplatinum as its sole hydrogenation-dehydrogenation component. That is tosay, the control catalyst was a combination of platinum and chlorinewith a gamma-alumina carrier material which was prepared by a manneranalogous to that given in Example I except for the inclusion of thegermanium component and contained, on an elemental basis, about 14 0.75Wt. percent platinum and about 0.85 wt. percent chlorine.

These catalysts were then separately subjected to a high stressevaluation test designed to determine their relative activity andselectivity for the reforming of a gasoline charge stock. In all teststhe same charge stock was utilized, its characteristics are given inTable I. It is to be noted that this test is conducted under asubstantially water-free condition with the only significant source ofwater being the 5.9 wt. p.p.m. present in the charge stock.

Table I-Analysis of heavy kuwait naphtha API gravity at 60 F. 60.4Initial boiling point, F. 184 10% boiling point, F. 205 50% boilingpoint, F. 256 boiling point, F. 321 End boiling point, F. 360 Sulfur,wt. p.p.m. 0.5 Nitrogen, wt. p.p.m. 0.1 Aromatic, vol. percent 8Parafiins, vol. percent 71 Naphthenes, vol. percent 21 Water, p.p.m. 5.9Octane No., F-l clear 40.0

This test was specifically designed to determine in a very short timeperiod whether the catalyst being evaluated has superior characteristicsfor the reforming process. It consists of six periods comprising a sixhour line-out period followed by a ten hour test period run at aconstant temperature during which time a 0 product reformate iscollected. It was performed in a laboratory scale reforming plantcomprising a reactor containing the catalyst, hydrogen separation zone,a debutanizer column, suitable heating, pumping, and condensing means,etc.

In this plant, a hydrogen recycle stream and the charge stock are'comrningled and heated to the desired conversion temperature. Theresulting mixture is then passed downflow into a reactor containing thecatalyst as a fixed bed. An efiiuent stream is then withdrawn from thebottom of the reactor, cooled to about 55 F., and passed to theseparating zone wherein a hydrogen-rich gaseous phase separates from aliquid phase. A portion of the gaseous phase is continuously passedthrough a high surface area sodium scrubber and the resultingsubstantially water-free hydrogen stream recycled to the reactor inorder to supply hydrogen for the reaction, and the excess over thatneeded for plant pressure is recovered as excess separator gas.Moreover, the liquid phase from the separating zone is withdrawntherefrom and passed to the debutanizer colum wherein light ends aretaken Overhead as debutanizer gas and a C reformate stream recovered asbottoms.

Conditions utilized in this test are: a constant temperature of about963 F. for the first three periods followed by a constant temperature ofabout 997 F. for the last three periods, a liquid hourly space velocityof 3.0, an outlet pressure of the reactor of p.s.i.g., and a mole ratioof hydrogen to hydrocarbon entering the reactor of 10:1.

This two temperature test is designed to quickly and efficiently yieldtwo points on the yield-octane curve for the particular catalysts. Theconditions utilized are selected on the basis of experience to yield themaximum amount of information on the capability of the catalyst beingtested to respond to a high severity operation.

The results of the separate tests performed on the catalyst of thepresent invention and the control catalyst are presented for each testperiod in Table II in terms of inlet temperature to the reactor in F.,net excess separator gas in standard cubic feet per barrel of charge(s.c.-f./bbl.), debutanizer overhead gas in standard cubic feet perbarrel, the ratio of the debutanizer gas make to the total gas make, andF-l clear octane number.

15 In addition, the respective catalysts were analyzed for carboncontent after the completion of test. The results showed that thecatalyst of the present invention contained 2.45 wt. percent carbonwhich was in marked contrast to the 4.17 wt. percent carbon which wasfound on the conperiod. The conditions employed were: an outlet reactorpressure of 100 p.s.i.g., a liquid hourly space velocity of 1.5 hr.- ahydrogen to hydrocarbon mole ratio of about 8:1 and an inlet reactortemperature which was continuously adjusted throughout the test in orderto achieve and trol catalyst. These results evidence an additionaladmaintain a C +reformate target octane of 102 F-l clear. vantage of thepresent invention which is the capability It is to be noted that theseare exceptionally severe conto suppress the rate of deposition ofcarbonaceous maditions. terials thereon during the course of thereforming reaction. The reforming plant utilized was identical instructure 10 and flow scheme to that described in Example II.

The results of the comparison test are recorded in Table III in terms oftemperature required to make oc- TABLE H RESULTS Tgl s REFORMING taine,C yield, and debutanizer and separator gas make.

Debutan- Separator Debutanizer gas] Octane Temp, gas, izer gas, totalgas No. F1

F. s.c.f./bbl. s.e.f./bbl. ratio clear TABLE IIL-RESULTS OF HIGH STRESSSTABILITY TEST Catalyst of the present invention (Weight percent),Separator Debutanizer 0.375 Pt, 0,25 Ga, and 0.85 01 05+, vol. gas, gas,Period No.: Temp., F. percent s.c.f., bbl. s.c.i.lbbl.

963 1,462 46 .030 95.1 Catalyst of the present invention (weight;percent), 0.375 963 1,456 47 031 95. 0 t, 0.25 Ge, and 0.85 or 997 1,682 51 .029 98. 6 Period No.: 997 1, 643 51 030 98. 5 1 964 77. 6 1, 73360 997 1, s22 49 029 98. 2 Control catalyst (Weight percent) Pt, and0.85 CI 25 963 1, 307 66 04s 91. 4 963 1, 23a 63 049 89. 5 963 1,196 66052 as. 9 997 1, 377 82 056 94. 0 997 1, 343 86 060 93. 3 997 1,303 87.062 92.3

Referring now to the results of the separate tests performedhh Table IL1S evldhht that efieht h the Referring to Table III, it is evident thatthe catalyst of germahlhm compfheht Oh the catalyst 15 to suhstahhahythe present invention is materially more stable than the P m the P methlcomponent ahd to enable a control catalyst under the conditions of thiscomparison catalysh'cohtalhlhg Plahhhm to ouhperform catalyst test. Thisstability feature is evident both in the area of contaihmg a suhstanhahygreater amount h h- 40 temperature stability and yield stability. Evenmore sur- Thflt 18 to y, the catalyst of the P qe 15 prising, C yieldfor the catalyst of the present inven- P Y hl to chhtrol catalyst. bothachvlty tion is consistently above that produced by the control andStahlhtlh Pomted ouhherelhheforeg a good catalyst throughout the test.Therefore, this accelerated measure of achvlty for a reforhhhg catalystOctane stability test provides additional evidence of the synernumber ofreformate produced at the same condrtrons; on gistic efiect f thegermanium compongnt on the platinumthis basis, the catalyst of thepresent invention was more containing catalyst active than the controlcatalyst at both temperature con- EXAMPLE IV ditions. However, activityis only half of the story: activity must be COllPlCd with selectivity [0demonstrate SUPGIlOIIiY. In rder to study the respgnses of the catalystof the selectivity is measured directly by reference to 5+ presentinvention to varying conditions in a reforming op- Y d and indirectly yfeferfincfi sfiPafatol' g mflkfi, eration, a sample of the catalystprepared by the method which is roughly Proportional to net y g makeWhich, of Example I was subjected to a four period test in which inturn, is a product of the preferred upgrading reactions, the pressure,the liquid hourly space velocity, and the conand by reference todebutanizer gas make which is a rough version temperature were varied ina manner calculated measure of undesired hydrocracking and Should beminito bring out the responses of the catalyst to changes in mized for ahighly selective catalyst. Referring again to pressure and changes inspace velocity.

the data presented in Table II and using the selectivity After aline-out period of 12 hours, a four period test criteria, it is manifestthat the catalyst of the present was f d, Th p periods were f 10 hourdura. invention is materially more selective than the control tionfollowed by a 10 hour line-out period, and the concatalyst. ditions usedin each period were as follows: for the first From consideration of thisdata, it is clear that gerperiod the pressure was 500 p.s.i.g., theliquid hourly mani m i an efilcient and effective promoter of aplatispace velocity was 1.5 hr.- and the conversion temperanum metalreforming catalyst. ture was 975 F.; for the second period the pressurewas 300 p.s.i.g., the liquid hourly space velocity was 1.5 hrf EXAMPLEIn and the temperature was 975 F.; for the third period the Order towmpare the Stability characteristics of the pressure was 300 p.s.i.g.,the liquid hourly space velocity catalyst of the present invention withthe control catalyst, was hrfr, and the cgnversion temperature was h ydiffeffiht comparison test was P This F.; and for the final period thepressure was 100 p.s.i.g., test was designed to measure, on anaccelerated basis, h li id hourly space velocity was 3.0 hr.- and thethe stability characteristics of the catalyst being tested tempgfatufewas 1050 F in a high Severity reforming Operation The COmPOShiOIIS Theresults of this test for the catalyst of the present of the catalysts py were identical to those describsd invention and the control catalystare presented in Table in Example II. N in terms of: octane number of (3product, debu- The test consisted of six periods of 24 hours with a 12tanizer gas make in s.c.f./bbl., net separator gas in s.c.f./ hourline-out period being followed by a 12 hour test bbl., and ratio ofdebutanizer gas make to totaigas make.

Catalyst 01 the present invention (Weight percent), 0.375 Pt, 0.25 Ge,0.85 01 Control catalyst (Weight percent), 0.75 Pt and 0.85 01 975 1. 5500 282 98. 9 387 985 975 1. 5 300 151 98. 8 225 1, 262 1, 020 3. 0 300155 97. 9 223 1, 221 1, 050 3. 0 100 087 94. 9 118 1, 233

By reference to the data presented in Table IV, it can be seen that thecatalyst of the present invention quite unexpectedly exhibitsmarkedly'superior performance at the low pressure conditions utilized.These results stand in sharp contrast to the generally poor performanceof the all platinum metal-containing control catalysts.

Accordingly, the catalyst of the present invention in a reformingembodiment finds optimum application at a low pressure condition ofabout 50 to about 350 p.s.i.g. This superior performance in the lowpressure domain is not paralleled by increased performance at highpressure conditions, and this response to the catalyst of the presentinvention to low pressure conditions is one of the singular and totallyunexpected advantages associated with the catalyst of the presentinvention.

I claim as my invention:

1. A catalytic composite comprising a combination of a platinum groupmetal, a germanium component, and a halogen component with a porouscarrier material, wherein substantially all of said platinum group metalis present as the elemental metal and substantially all of saidgermanium component is present in an oxidation state above that of theelemental metal, and wherein said components are present amountssuflicient to result in the composite containing, on an elemental basis,about 0.01 to about 2.0 wt. percent of the platinum group metal, about0.01 to about 5.0 wt. percent of germanium, and about 0.5 to about 3.5wt. percent halogen.

2. A catalytic composite as defined in claim 1 wherein said platinumgroup metal is platinum.

3. A catalytic composite as defined in claim 1 wherein said germaniumcomponent is germanium oxide or sulfide.

4. A catalytic composite as defined in claim 1 wherein said halogencomponent is chlorine or a compound of chlorine.

5. A catalytic composite as defined in claim 1 wherein said porouscarrier material is a refractory inorganic oxide.

6. A catalytic composite as defined in claim 5 wherein said refractoryinorganic oxide is gammaor eta-alumina.

7. A catalytic composite as defined in claim 1 wherein said compositecontains, on an elemental basis, about 0.05 to about 1.0 wt. percent ofthe platinum group metal, about 0.05 to about 2.0 wt. percent ofgermanium, and about 0.6 to about 1.2 wt. percent halogen.

8. A catalytic composite as defined in claim 1 wherein the atomic ratioof germanium to the platinum group metal contained in the composite isabout 0.111 to about 5:1.

9. A catalytic composite comprising a combination of platinum, agermanium oxide component, and a halogen component with an aluminacarrier material in amounts suflicient to result in the compositecontaining, on an elemental basis, about 0.01 to about 2.0 wt. percentplatinum, about 0.01 to about 5.0 wt. percent germanium, and about 0.5to about 3.5 wt. percent halogen, substantially all of said platinumbeing present as the elemental metal and substantially all of saidgermanium being present in an oxidation state above that of theelemental metal.

10. A catalytic composite as defined in claim 9 wherein said halogencomponent is chlorine or a compound of chlorine.

11. A catalytic composite comprising a combination of the catalyticcomposite of claim 9 with a sulfur component in amounts sufiicient toincorporate about 0.05 to about 0.5 wt. percent sulfur, calculated on anelemental basis.

12. A catalytic composite as defined in claim 9 wherein the atomic ratioof germanium to platinum contained in the composite is about 0.1:1 toabout 5 :1.

13. A catalytic composite as defined in claim 9 wherein said compositecontains about 0.05 to about 1.0 wt. percent platinum, about 0.05 toabout 2.0 wt. percent germanium, and about 0.6 to about 1.2 wt. percenthalogen.

14. A catalytic composite as defined in claim 13 wherein the atomicratio of germanium to platinum contained in the composite is about 0.2:1to about 3.521.

15. A process for converting a hydrocarbon which comprises contactingthe hydrocarbon with the catalytic composite of claim 1 at hydrocarbonconversion conditions.

16. A processes for reforming a gasoline fraction which comprisescontacting the gasoline fraction and hydrogen with the catalyticcomposite of claim 9 at reforming conditions.

17. A process as defined in claim 16 wherein said reforming conditionsinclude a temperature of about 800 to about 1100 F., a pressure of about50 to about 350 p.s.i.g., a liquid hourly space velocity of about 0.1 toabout 10 hrr and a mole ratio of hydrogen to hydrocarbon of about 1 toabout 20 moles of hydrogen per mole of hydrocarbon.

18. A process as defined in claim 16 wherein said contacting isperformed in a substantially water-free environment.

19. A process for reforming a gasoline fraction which comprisescontacting the gasoline fraction and hydrogen with the catalyticcomposite of claim 13 at reforming conditions including a pressure ofabout 50 to about 350 p.s.1.g.

20. A process as defined in claim 19 wherein said contacting isperformed in a substantially water-free environment.

References Cited UNITED STATES PATENTS 2,784,147 3/1957 Strecker et a1252-463 2,796,410 6/1957 Strecker et al. 252-466 2,861,959 11/1958 Thornet a1 208-138 2,906,701 9/1959 Stine et a1. 208-138 3,502,573 3/1970Pollitzer et a1 208-138 HERBERT LEVINE, Primary Examiner US. Cl. X.R.

